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Abstract:

A razor cartridge is provided comprising a housing having a base which is
connectable to a handle, two or more blades, whose tips are aligned in a
cutting plane to cut in a cutting direction, and a moisturizing block
disposed before and/or after the blades in the cutting direction, the
moisturizing block having a skin-contacting surface, wherein: the
moisturizing block comprises at least 50% lipophilic materials by weight
of the moisturizing block; and from about from about 0.01% to 5% of an
anti-irritation agent comprising a pyrithione, a polyvalent metal salt of
pyrithione, and a mixture thereof, such as zinc pyrithione.

Claims:

1. A razor cartridge suitable for use on a razor handle, said razor
cartridge comprising a housing having a base which is connectable to a
handle, two or more blades, whose tips are aligned in a cutting plane to
cut in a cutting direction (A), and a moisturizing block disposed before
and/or after the blades in the cutting direction (A), the moisturizing
block having a skin-contacting surface, wherein: the moisturizing block
comprises at least 50% lipophilic materials by weight of the moisturizing
block and from about 0.01% to 5% of an anti-irritation agent comprising a
pyrithione, a polyvalent metal salt of pyrithione, and a mixture thereof.

2. The razor cartridge of claim 1, wherein said level of anti irritation
agent is from about 0.25% to about 2.5%.

4. The razor cartridge of claim 3, further comprising from 0.001% to 10%
of a zinc salt.

5. The razor cartridge of claim 3, wherein the zinc pyrithione is in
platelet particle form having an average size of up to about 20 mm.

6. The razor cartridge of claim 3, wherein said zinc pyrithione is in the
form of a platelet having a median particle diameter of about 0.5 microns
to about 10, a mean particle diameter of about 0.5 to about 10 microns,
and a thickness of about 0.6 to about 15 microns.

7. The skin engaging member of claim 6, wherein the mean particle
diameter of the platelet ZPT is about 2 microns to about 4 microns.

8. The razor cartridge of claim 6, wherein the median particle diameter
of the platelet ZPT is about 1 micron to about 5 microns.

9. The razor cartridge of claim 1, wherein the skin-contacting surface
slopes away from the blades towards the base.

10. The razor cartridge of claim 1, wherein the moisturizing block
comprises from 60% to 95%, preferably from 70% to 90% lipophilic
materials by weight of the moisturizing block.

12. The razor cartridge of claim 1, wherein the moisturizing block
comprises wax and preferably the moisturising block comprises from 2% to
20% and more preferably from 3% to 15% wax by weight of the moisturising
block.

14. The razor cartridge of claim 1, wherein the moisturizing block
comprises from 2% to 50%, preferably from 3% to 40%, more preferably 4%
to 12% of a structuring polymer by weight of the moisturizing block.

16. The razor cartridge of claim 1, wherein the moisturizing block is
disposed after the cutting blades in the cutting direction (A).

17. The razor cartridge of claim 1, wherein said moisturizing block
further comprises a malodor control agent.

18. A razor cartridge suitable for use on a razor handle, said razor
cartridge comprising a housing having a base which is connectable to a
handle, two or more blades, whose tips are aligned in a cutting plane to
cut in a cutting direction (A), and a moisturizing block disposed before
and/or after the blades in the cutting direction (A), the moisturizing
block having a skin-contacting surface, wherein: the moisturizing block
comprises at least 50% lipophilic materials by weight of the moisturizing
block and from about 0.01% to 5% of an active comprising a solid particle
in platelet form having an average size of up to about 20 μm.

19. The razor cartridge of claim 18, wherein said solid particle is in
the form of a platelet having a median particle diameter of about 0.5
microns to about 10, a mean particle diameter of about 0.5 to about 10
microns, and a thickness of about 0.6 to about 15 microns.

20. The razor cartridge of claim 18, wherein the mean particle diameter
of the platelet is about 2 microns to about 4 microns.

Description:

CROSS REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to U.S. Application No.
61/524,097, filed Aug. 16, 2011 and U.S. application Ser. No. 13/528,932
filed on Jun. 21, 2012, which claims priority to EP Application No.
11171369.9, filed Jun. 24, 2011, the subject of which is hereby
incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] Hair removal devices incorporating a chemical composition are known
and shall be referred to herein as devices comprising an "onboard"
composition. Reference can be made to WO 07/056,509 which teaches the
inclusion of an onboard soap composition in a wet shaving razor. It is
also known to provide a wet shaving razor incorporating an onboard
skin-engaging composition comprising large quantities of hydrophilic
polymers, such as polyethylene oxide, to lubricate the skin. Reference is
made, by way of example, to WO 97/02116 and WO 97/02117.

[0003] The patent applications referred to above relate to the provision
of various advantages, such as additional lathering and soap-related
benefits, or improved lubrication in the case of polyethylene oxide. It
would alternatively or additionally be advantageous to be able to provide
a skin moisturizing benefit via an onboard chemistry, especially to male
users who may be less motivated to use skin moisturizers than females.
The provision of a moisturizing benefit from an onboard chemistry may,
however, have a number of difficulties associated with it.

[0004] Skin moisturization may be achieved in several different ways, but
one important formulational route to achieving skin moisturization is to
include materials which bind water, such as polyols. However, such
materials derive their water-binding abilities in part from their
significant hydrophilicity, which may render them unsuited for use in any
context involving water, such as is the case during wet shaving--they may
be washed away during the initial stages of a shave. An alternative
approach might be to use occlusive, hydrophobic materials which cover the
skin and therefore act to retain water already present therein. These
materials are emollients which are less likely to be washed away during
use in a highly aqueous environment. WO 06/108522, discloses the use of
small amounts of hydrophobic emollients in an onboard chemistry. However,
formulations comprising significant proportions of hydrophobic emollients
may give rise to increased drag across the skin, due to the affinity of
such materials with the hydrophobic skin surface. Users report that
increased drag tends to increase discomfort during shaving. US
2009/0223057 discloses shaving aid strip compositions comprising
polyoxyethylene for similar reasons to the above-discussed prior art. In
order to improve the longevity of the shaving aid, the polyoxyethylene is
mixed with amphipathic, but generally hydrophobic materials, such as
fatty alcohols.

SUMMARY OF THE INVENTION

[0005] According to a first aspect of the invention, a razor cartridge is
provided comprising a housing having a base which is connectable to a
handle, two or more blades, whose tips are aligned in a cutting plane to
cut in a cutting direction, and a moisturizing block disposed before
and/or after the blades in the cutting direction, the moisturizing block
having a skin-contacting surface, wherein: the moisturizing block
comprises at least 50% lipophilic materials by weight of the moisturizing
block from about 0.01% to 5% of an anti-irritation agent comprising a
zinc pyrithione, a zinc salt, or a combination thereof.

[0006] According to a second aspect of the invention, a razor is provided
comprising a cartridge according to the first aspect of the invention.

[0007] According to a third aspect of the invention, the use of the razor
according to the second aspect of the invention is provided, to remove
hair and moisturize the skin.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1. is a view of a razor cartridge according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0009] According to the invention, a razor cartridge is provided
comprising at least two blades whose tips are aligned in a cutting plane
to cut in a cutting direction. The razor cartridge comprises a housing
having a base. The base is connectable to a handle via means known to the
man skilled in this art and which need not be elaborated here.

[0010] The razor cartridge according to the invention comprises a
moisturizing block. The moisturizing block is configured to be erodable,
such that it erodes during and as a result of shaving human skin to leave
moisturizing deposits on the skin. As used herein, the word "erodable",
when used in relation to the moisturizing block, includes a moisturizing
block having a Chatillon Hardness at 25° C. of 0.50-3.25 kg,
preferably 0.75-3.00 kg, more preferably 1.00-2.50 kg, measured according
to the protocol provided hereinbelow. Within these ranges, beneficial
rates of wear may be achieved. In order to provide effective
moisturization, the moisturizing block comprises at least 50%, preferably
from 60% to 95% and more preferably from 70% to 90% lipophilic materials
by weight of the moisturizing block.

[0012] Advantageously, if solids or semi-solids are present, then the
moisturizing block comprises less than 20% and preferably less than 5% by
weight of the moisturizing block of materials, and more preferably no
materials at all, having a melting point of more than 100° C. This
is because excessive quantities of such materials may render the
moisturizing block inflexible and therefore liable to crack during
manufacture and/or use.

[0013] Liquid, semi-solid, or solid hydrocarbon lipophilic materials which
may be comprised within the moisturizing block include straight chain,
branched chain, saturated and unsaturated hydrocarbons and mixtures
thereof and they may comprise natural or synthetic hydrocarbon emollients
and mixtures thereof. Preferred natural hydrocarbon emollients include
petrolatum, mineral oil and mixtures thereof. Preferred synthetic
hydrocarbon emollients include branched chain hydrocarbons, such as
isohexadecane (such as Arlamol HD® from Croda) and Polydecene (such as
Puresyn 2® from Exxon Mobil).

[0014] Liquid, semi-solid, or solid fatty alcohol or fatty acid emollients
which may be comprised within the moisturizing block include saturated
and unsaturated higher alcohols, especially C12-C30 fatty
alcohols and fatty acids, especially lauric, myristic, palmitic, stearic,
arachidic or behenic. Liquid, semi-solid, or solid ester emollients which
may be comprised within the moisturizing block include esters of a
C12-C30 alcohol and mixtures thereof, especially isopropyl
myristate, isopropyl isostearate and mixtures thereof.

[0015] Liquid, semi-solid, or solid triglyceride emollients which may be
comprised within the moisturizing block include synthetic or natural
triglycerides, especially natural triglycerides derived from sunflower,
avocado, olive, castor, coconut, cocoa and mixtures thereof. More
preferred are coconut-derived triglycerides, such as the commercially
available materials Myritol® 312 and 318 (Cognis), Estasan® (Croda)
and Miglyol® (Sasol).

[0016] Liquid, semi-solid, or solid fat and butter emollients which may be
comprised within the moisturizing block include coconut butter, shea
butter and mixtures thereof.

[0017] Liquid, semi-solid, or solid wax emollients which may be comprised
within the moisturizing block include paraffin wax, microcrystalline wax,
candellila, ozokerite and mixtures thereof, preferably paraffin wax.
Advantageously, moisturizing block comprises some wax because waxes may
bestow improved hardness and erodability to the moisturising block,
although, as discussed above, the presence of too much wax may render the
composition inflexible and therefore liable to crack during manufacture
and/or use. Preferably, the moisturising block comprises from 2% to 20%
and more preferably from 3% to 15% wax by weight of the moisturising
block.

[0018] Liquid, semi-solid, or solid lipophilic skin active agents which
may be comprised within the moisturizing block include oil soluble
vitamins and agents which have activity on skin, such as vitamin E
derivatives, including vitamin E acetate and tocopherol nicotinate;
oil-soluble vitamin A derivatives, such as retinyl palmitate; lanolin;
ceramides; sterols and sterol esters; salicylic acid; camphor;
eucalyptol; essential oils and mixtures thereof.

Anti-Irritation Agent

[0019] In one embodiment the shave preparation composition of the present
invention further comprises an anti-irritation agent. The anti-irritation
agent can be pyrithione or a polyvalent metal salt of pyrithione, or a
mixture thereof. Any form of polyvalent metal pyrithione salts may be
used, including platelet and needle structures. Preferred salts for use
herein include those formed from the polyvalent metals magnesium, barium,
bismuth, strontium, copper, zinc, cadmium, zirconium and mixtures
thereof, more preferably zinc. Even more preferred for use herein is the
zinc salt of 1-hydroxy-2-pyridinethione (known as "zinc pyrithione" or
"ZPT"); more preferably ZPT in platelet particle form, wherein the
particles have an average size of up to about 20 μm, preferably up to
about 5 μm, more preferably up to about 2.5 μm. Pyridinethione
anti-microbial and anti-dandruff agents are described, for example, in
U.S. Pat. No. 2,809,971; U.S. Pat. No. 3,236,733; U.S. Pat. No.
3,753,196; U.S. Pat. No. 3,761,418; U.S. Pat. No. 4,345,080; U.S. Pat.
No. 4,323,683; U.S. Pat. No. 4,379,753; and U.S. Pat. No. 4,470,982.

[0020] Preferred embodiments include from 0.01% to 5% of an
anti-irritation agent; alternatively from 0.05% to 2%, alternatively from
0.1% to 1%, alternatively from 0.2% to about 0.7%, alternatively about
0.5%.

[0021] In one embodiment, the anti-irritation agent is a solid particle in
the form of a platelet as described here.

[0022] The composition of the present invention optionally includes an
effective amount of a zinc salt. Preferred embodiments of the present
invention include an effective amount of a zinc salt having an aqueous
solubility within the composition of less than about 25%, by weight, at
25° C., more preferably less than about 20%, more preferably less
than about 15%. Preferred embodiments of the present invention include
from 0.001% to 10% of a zinc salt, more preferably from 0.01% to 5%, more
preferably still from 0.1% to 3%. In a preferred embodiment, the zinc
salt has an average particle size of from 100 nm to 30 μm.

[0024] In embodiments having an anti-irritation agent and a zinc salt, the
ratio of zinc salt to anti-irritation agent is preferably from 5:100 to
5:1; more preferably from about 2:10 to 3:1; more preferably still from
1:2 to 2:1.

[0025] Those of skill in the art will understand that the anti-irritation
agent of the present invention can also have other benefits which may be
desirable from a skin care composition, including but not limited to
malodor control and/or anti-bacterial benefits depending on whether the
composition is left on skin or rinsed off.

[0026] Without intending to be bound by theory, it is believed that these
anti-irritation agents can provide various benefits including reduction
or control of irritation as well as certain malodor control. In one
embodiment, the composition further comprises other agents such as
malodor control agents. The malodor active of the present invention is
capable of providing an antimicrobial benefit. Such malodor actives are
capable of destroying microbes, preventing the development of microbes or
preventing the pathogenic action of microbes. A safe and effective amount
of a malodor active may be added to the intimate cleansing product, at
from about 0.001% to about 10%, or from about 0.01% to about 5%, or from
about 0.05% to about 2%, or from about 0.1% to about 1%, or from about
0.3% to about 0.7%, or about 0.5% by weight of the composition.

[0028] The moisturizing block according to the invention may be disposed
before and/or after the blades in the cutting direction, but is
preferably disposed after the blades. The moisturizing block comprises a
skin-contacting surface which may be planar or may define a shallow
convex and/or concave curve. Advantageously, the skin-contacting surface
is planar, because a planar surface may provide a higher surface area for
deposition than a convex or concave surface. The skin-contacting surface
slopes away from the blades towards the base of the razor cartridge. This
feature may reduce the drag experienced by users, while facilitating
deposition of moisturiser by the moisturising block. Advantageously, the
skin-contacting surface slopes such that all tangents to the
skin-contacting surface slope at an acute angle, α, to the cutting
plane. More advantageously, the angle, α, is from 5° to
15°.

[0029] The moisturizing block may additionally comprise a structuring
polymer. Preferably, the moisturizing block comprises from 2% to 50%,
preferably from 3% to 40%, more preferably 4% to 12% of structuring
polymer by weight of the moisturizing block.

[0030] As defined herein, the structuring polymer is not regarded as being
one of the "lipophilic materials" as defined above and should be ignored
for the purposes of calculating the percentage weights of the "lipophilic
materials".

[0031] Advantageously, the structuring polymer comprises a block
copolymer. More advantageously, the block copolymer comprises a di-block
copolymer, a tri-block copolymer, a multi-block copolymer, a radial block
copolymer, a random block copolymer, or a mixture of these polymers.

[0032] In the case in which the block copolymer comprises a tri-block
copolymer, then the tri-block copolymer preferably comprises a linear ABA
tri-block polymer. Without wishing to be bound by theory, applicants
believe that the A blocks aggregate creating domains, within which the
moisturizing hydrophobic phase may accumulate, connected together by the
B-blocks. This structure may provide an appropriate hardness to bestow
the requisite wear properties to the moisturizing block, while also being
flexible enough to be processed and not to crack or break during
processing and/or use.

[0035] As discussed above, the structuring polymer comprised within the
moisturizing block may comprise a random block copolymer. An example of a
suitable random block copolymer is ethylene vinyl acetate (EVA) which is
a copolymer of ethylene and vinyl acetate. Advantageously, the amount of
ethylene comprised within the EVA polymer is from 65-90%, preferably from
70-85% by weight of the EVA to give beneficial wear properties. A
commercially available range of EVA is called Elvax®, which is
commercialised by DuPont.

[0036] The moisturizing block may comprise one or more additional
components which bestow a suitable melt viscosity to the composition,
such as oil phase gellants, to facilitate improved processing, provided
that the additional component(s) do not significantly reduce the hardness
or erodability of the moisturizing block. Examples of such components are
trihydroxystearin, which is commercially available as Thixcin R®
(manufactured by Elementis Specialities), ethylene vinyl acetate (EVA)
and mixtures thereof.

[0037] A moisturizing block according to the invention may be manufactured
by heating the lipophilic materials to a suitable temperature to melt
them, typically approximately 130° C., after which the structuring
polymer is added and mixed well until the structuring polymer has
dissolved. The mixture is then cooled, typically to approximately
90° C., after which any additional ingredients may be added. In a
final step, the mixture is poured into suitable containers or moulds and
allowed to cool to room temperature.

[0038] Once the mixture has set to form a moisturizing block, it may be
affixed to a razor cartridge in any appropriate fashion. One such
approach is to mould the moisturizing block directly onto the cartridge.
Another approach involves directly or indirectly adhering the
moisturizing block to the cartridge by means of an adhesive composition.
One method of indirect adherence involves casting the moisturizing block
onto a sheet of an appropriate substrate, such as an acetate sheet, which
sheet is then adhered to the cartridge, for example mechanically or via
an adhesive.

[0039] FIG. 1 depicts a non-limiting example of a razor cartridge (1)
according to the invention. The cartridge (1) comprises a housing having
a base (2) which is connectable to a handle using means known to the
skilled person in this field. The cartridge (1) comprises blades (3)
whose tips are aligned in a cutting plane (4) to cut in a cutting
direction (A). The cartridge also comprises a moisturizing block (5). In
this execution it is disposed after the blades (3), although it may
instead or additionally be disposed before the blades (3). The
moisturizing block (5) comprises skin-contacting surface (6), which
slopes away from the blades (3) towards the base (2) at an angle,
α, to the cutting plane (4). This embodiment also comprises a front
skin-engaging element (7) and a rear skin-engaging element (8).

[0042][0043] 1. Prepare Chatillon TCD 200 and digital force gauge
according to manufacturers instructions. [0044] 2. Set the ramp speed to
47 mm/min B) Measuring the hardness value at 25° C.: [0045] 1. The
pointed geometry should be attached to the shaft of ramp for this test
method. [0046] 2. Place the moisturizing block as prepared above and on
its side onto the metal base plate directly below the centre of the shaft
of the ramp. The mid-point of the moisturizing block should be in line
with the centre of the shaft of the ramp. [0047] 3. With the moisturizing
block in place below the flat plate the speed set at 47 mm/min and the
digital force gauge set at "C Peak" as above, depress the "Down" button
on the Chatillon TCD200. [0048] 4. Stop the Chatillon TCD200 just as the
probe touches the surface of the moisturizing block and set the distance
counter to zero. [0049] 5. Reset the force gauge so that it reads zero
[0050] 6. Depress the "Down" button on the Chatillon TCD200 until the
distance counter reads 13 mm, record C Peak reading.

Example

[0051] The following example discloses a moisturizing block according to
the invention, which was incorporated into a razor cartridge as a strip
disposed after the blade in the cutting direction. In use, when attached
to a razor, the razor cartridge was observed to remove hair and
moisturize the skin from which hair had been removed.

[0052] The composition of Example 1 was manufactured by heating the
hydrocarbons and waxes to 130° C., then adding the linear ABA
tri-block polymer (Kraton G1650E) and mixing well until polymer was fully
dissolved. The mixture was then cooled to 90° C. and the Thixcin
added, after which the mixture was moulded onto the cartridge and allowed
to cool to room temperature.

[0053] The Chatillon Hardness of the formulation of Example 1 is 1.7 and
the angle, α, was moulded to be 12.4°.

[0054] The dimensions and values disclosed herein are not to be understood
as being strictly limited to the exact numerical values recited. Instead,
unless otherwise specified, each such dimension is intended to mean both
the recited value and a functionally equivalent range surrounding that
value. For example, a dimension disclosed as "40 mm" is intended to mean
"about 40 mm".